1. Field of the Invention
The present invention relates to a plasma processing method and a plasma processing apparatus, and particularly to a plasma enhanced CVD (Chemical Vapor Deposition) method and a plasma enhanced CVD apparatus which are used for manufacturing semiconductor devices and liquid crystal display (LCD) devices.
2. Description of the Related Art
According to a conventional CVD method, while the interior pressure of a processing chamber is being controlled at a predetermined pressure through use of a predetermined gas, an RF power is applied between a cathode and an anode by an RF generator so as to generate plasma to thereby form a film on a substrate placed on a substrate table.
After the elapse of a predetermined period of time required to form the film, the application of the RF power, the feed of the reaction gas, and the pressure control of the processing chamber are simultaneously terminated, and the processing chamber is evacuated to establish a high vacuum therein. After the interior of the processing chamber reaches a predetermined degree of vacuum, the substrate is lifted off the substrate table, and subsequently the substrate is taken out from the processing chamber by a transfer robot.
However, in the case where a substrate is transferred in accordance with the above-described sequence of the conventional plasma enhanced CVD method after the formation of a film on the substrate, a transfer error occurs in some cases due to the following causes: the substrate remains adhered to an adjacent cathode while being transferred; the substrate once adheres to the cathode and then drops onto the substrate table; and the dropped substrate breaks. Furthermore, in some cases, the substrate sparks to a nearby grounded site. Such a spark blows out a part of the formed film or a device pattern, resulting in pattern missing. This has lead to a so-called dielectric breakdown wherein an insulated portion breaks down. As a result of such a potential substrate transfer error or dielectric breakdown, the sequence of the conventional plasma enhanced CVD method fails to provide a stable film formation process.